Mobile object control device, mobile object control method, and storage medium

ABSTRACT

A mobile object control device acquires an image obtained by imaging an outside space of a mobile object, determines whether the mobile object is in a merging lane closer to a merged lane between two merging lanes, determines whether another mobile object is in a merging lane farther from the merged lane between the merging lanes in front of the mobile object when it is determined that the mobile object is in the closer merging lane, sets one or more merging position candidates at which merging of the mobile object to the merged lane is completed and which are positions between mobile objects in the merged lane, and selects a merging position at which the merging of the mobile object to the merged lane is completed from the one or more merging position candidates.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed on Japanese Patent Application No. 2021-043098,filed on Mar. 17, 2021, the content of which is incorporated herein byreference.

BACKGROUND Field of the Invention

The present invention relates to a mobile object control device, amobile object control method, and a storage medium.

Description of Related Art

Technologies for supporting entrance of vehicles traveling in merginglanes to merged lanes are known. Japanese Unexamined Patent Application,First Publication No. 2019-192233 discloses a technology for predictingbehaviors of a plurality of vehicles based on a behavior predictionmodel at the time of merging to a merged lane and indicating a mergingposition based on the prediction.

SUMMARY

However, the technology disclosed in Japanese Unexamined PatentApplication, First Publication No. 2019-192233 does not specificallyconsider a case in which there are two merging lanes. As a result, whenthe number of merging lanes are 2, a merging position cannotappropriately be indicated.

The present invention is devised in view of such circumstances and anobjective of the present invention is to provide a mobile object controldevice, a mobile object control method, and a storage medium capable ofappropriately indicating a merging position when the number of merginglanes is two.

A mobile object control device according to aspects of the presentinvention has the following configurations.

(1) According to an aspect of the present invention, a mobile objectcontrol device includes a storage device storing a program and ahardware processor. The hardware processor executes the program storedin the storage device to acquire an image obtained by imaging an outsidespace of a mobile object; to determine whether the mobile object is in amerging lane closer to a merged lane between two merging lanes, based onthe image; to determine whether another mobile object is in a merginglane farther from the merged lane between the merging lanes in front ofthe mobile object when it is determined that the mobile object is in thecloser merging lane; to set one or more merging position candidates atwhich merging of the mobile object to the merged lane is completed andwhich are positions between mobile objects in the merged lane; to selecta merging position at which the merging of the mobile object to themerged lane is completed from the one or more merging positioncandidates; and to select the merging position from the merging positioncandidates excluding a merging position candidate located in front withrespect to a traveling direction of the mobile object among the one ormore merging position candidates when the hardware processor determinesthat there are other mobile objects.

(2) In the mobile object control device according to the aspect (1), thehardware processor may set a perpendicular drawn from the mergingposition candidate located in front with respect to the travelingdirection of the mobile object on an assumed plane virtually seen fromthe above, compare a first distance between the mobile object and thevirtual line with a second distance between the other mobile object andthe virtual line, and determine that the other mobile object is in frontof the mobile object when the second distance is shorter than the firstdistance.

(3) In the mobile object control device according to the aspect (1), thehardware processor may estimate a traveling trajectory of the othermobile object and determine whether the other mobile object is able tomerge to the merging position candidate located in front based on thetraveling trajectory. When the hardware processor determines that theother mobile object is not able to merge to the merging positioncandidate located in front, the hardware processor may select themerging position from the merging position candidates excluding amerging position candidate located in front and a merging positioncandidate located in a second place in the traveling direction of themobile object among the one or more merging position candidates.

(4) In the mobile object control device according to the aspect (1), thehardware processor may estimate a time until an occupant of the mobileobject manipulates a brake device of the mobile object. When theestimated time is less than a threshold, the hardware processor mayselect the merging position from the one or more merging positioncandidates without excluding the merging position candidate located infront with respect to the traveling direction of the mobile object.

(5) In the mobile object control device according to the aspect (1), thehardware processor may keep selecting the merging position even when theother mobile object is decelerated after the selection of the mergingposition from the merging position candidates excluding the mergingposition candidate located in front.

(6) In the mobile object control device according to the aspect (1), thehardware processor may generate a target trajectory of the mobile objectmerging to the selected merging position and control steering andacceleration or deceleration of the mobile object without depending on amanipulation of a driver of the mobile object such that the mobileobject travels along the generated target trajectory.

(7) According to another aspect of the present invention, a mobileobject control method causes a computer mounted in a vehicle: to acquirean image obtained by imaging an outside space of a mobile object; todetermine whether the mobile object is in a merging lane closer to amerged lane between two merging lanes, based on the image; to determinewhether another mobile object is in a merging lane farther from themerged lane between the merging lanes in front of the mobile object whenit is determined that the mobile object is in the closer merging lane;to set one or more merging position candidates at which merging of themobile object to the merged lane is completed and which are positionsbetween mobile objects in the merged lane; to select a merging positionat which the merging of the mobile object to the merged lane iscompleted from the one or more merging position candidates; and toselect the merging position from the merging position candidatesexcluding a merging position candidate located in front with respect toa traveling direction of the mobile object among the one or more mergingposition candidates when the hardware processor determines that thereare other mobile objects.

(8) According to still another aspect of the present invention, acomputer-readable non-transitory storage medium stores a program causinga computer mounted in a mobile object: to acquire an image obtained byimaging an outside space of a mobile object; to determine whether themobile object is in a merging lane closer to a merged lane between twomerging lanes, based on the image; to determine whether another mobileobject is in a merging lane farther from the merged lane between themerging lanes in front of the mobile object when it is determined thatthe mobile object is in the closer merging lane; to set one or moremerging position candidates at which merging of the mobile object to themerged lane is completed and which are positions between mobile objectsin the merged lane; to select a merging position at which the merging ofthe mobile object to the merged lane is completed from the one or moremerging position candidates; and to select the merging position from themerging position candidates excluding a merging position candidatelocated in front with respect to a traveling direction of the mobileobject among the one or more merging position candidates when thehardware processor determines that there are other mobile objects.

According to the aspects (1) to (8), it is possible to appropriatelyindicate a merging position when the number of merging lanes is 2.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a vehicle system inwhich a mobile object control device according to an embodiment is used.

FIG. 2 is a diagram illustrating a functional configuration of first andsecond controllers.

FIG. 3 is a diagram illustrating an example of a scenario in which aprocess of a mobile object control device according to an embodiment isperformed.

FIG. 4 is a diagram illustrating an example of a scenario in which amerging position selector selects a merging position when a thirddeterminer determines that another vehicle cannot merge to a mergingposition candidate located in front.

FIG. 5 is a diagram illustrating an example of a scenario in which anown vehicle is located in front of another vehicle as a decelerationresult of the other vehicle after a merging position selector selects amerging position.

FIG. 6 is a flowchart illustrating an exemplary flow of a process of themobile object control device according to the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of a mobile object control method, and astorage medium according to the present invention will be described withreference to the drawings. A mobile object in the present invention is afour-wheeled vehicle, a two-wheeled vehicle, a micro-mobility, a robot,or the like. In the following description, a mobile object is assumed tobe a four-wheeled vehicle.

Overall Configuration

FIG. 1 is a diagram illustrating a configuration of a vehicle system 1in which a mobile object control device according to an embodiment isused. A vehicle in which the vehicle system 1 is mounted is, forexample, a vehicle such as a two-wheeled vehicle or a four-wheeledvehicle and a driving source of the vehicle is an internal combustionengine such as a diesel engine or a gasoline engine, an electric motor,or a combination thereof. The electric motor operates using powergenerated by a power generator connected to the internal combustionengine or power discharged from a secondary cell or a fuel cell.

The vehicle system 1 includes, for example, a camera 10, a radar device12, a light detection and ranging (LIDAR) 14, an object recognitiondevice 16, a communication device 20, a human machine interface (HMI)30, a vehicle sensor 40, a navigation device 50, a map positioning unit(MPU) 60, a driving operator 80, an automated driving control device100, a travel driving power output device 200, a brake device 210, and asteering device 220. The devices and units are connected to one anothervia a multiplex communication line such as a controller area network(CAN) communication line, a serial communication line, or a wirelesscommunication network. The configuration shown in FIG. 1 is merelyexemplary, a part of the configuration may be omitted, and anotherconfiguration may be further added.

The camera 10 is, for example, a digital camera that uses a solid-stateimage sensor such as a charged coupled device (CCD) or a complementarymetal oxide semiconductor (CMOS). The camera 10 is mounted on anyportion of a vehicle in which the vehicle system 1 is mounted(hereinafter referred to as the own vehicle M). When the camera 10images a front side, the camera 10 is mounted on an upper portion of afront windshield, a rear surface of a rearview mirror, or the like. Forexample, the camera 10 repeatedly images the surroundings of the ownvehicle M periodically. The camera 10 may be a stereo camera.

The radar device 12 radiates radio waves such as millimeter waves to thesurroundings of the own vehicle M and detects radio waves (reflectedwaves) reflected from an object to detect at least a position (adistance and an azimuth of) of the object. The radar device 12 ismounted on any portion of the own vehicle M. The radar device 12 maydetect a position and a speed of an object in conformity with afrequency modulated continuous wave (FM-CW) scheme.

The LIDAR 14 radiates light (or electromagnetic waves with a wavelengthclose to light) to the surroundings of the own vehicle M and measuresscattered light. The LIDAR 14 detects a distance to a target based on atime from light emission to light reception. The radiated light is, forexample, pulsed laser light. The LIDAR 14 or a plurality of finders 14are mounted on any portions of the own vehicle M.

The object recognition device 16 performs a sensor fusion process ondetection results from some or all of the camera 10, the radar device12, and the LIDAR 14 and recognizes a position, a type, a speed, and thelike of an object. The object recognition device 16 outputs arecognition result to the automated driving control device 100. Theobject recognition device 16 may output detection results of the camera10, the radar device 12, and the LIDAR 14 to the automated drivingcontrol device 100 without any change. In the embodiment, the objectrecognition device 16 includes an image acquirer 16A. The image acquirer16A acquires an image of an outside space of a vehicle captured by thecamera 10 and outputs the image to the automated driving control device100 to be described below.

The communication device 20 communicates with another vehicle around theown vehicle M or various server devices via radio base stations using,for example, a cellular network, a Wi-Fi network, Bluetooth (registeredtrademark), dedicated short range communication (DSRC) or the like.

The HMI 30 presents various types of information to occupants of the ownvehicle M and receives input operations by the occupants. The HMI 30includes, for example, various display devices, speakers, buzzers, touchpanels, switches, and keys.

The vehicle sensor 40 includes a vehicle speed sensor that detects aspeed of the own vehicle M, an acceleration sensor that detects anacceleration, a yaw rate sensor that detects angular velocity around avertical axis, and an azimuth sensor that detects an orientation of theown vehicle M.

The navigation device 50 includes, for example, a global navigationsatellite system (GNSS) receiver 51, a navigation HMI 52, and a routedeterminer 53. The navigation device 50 retains first map information 54in a storage device such as a hard disk drive (HDD) or a flash memory.The GNSS receiver 51 identifies a position of the own vehicle M based onsignals received from GNSS satellites. The position of the own vehicle Mmay be identified or complemented by an inertial navigation system (INS)using an output of the vehicle sensor 40. The navigation HMI 52 includesa display device, a speaker, a touch panel, and a key. The navigationHMI 52 may be partially or entirely common to the above-described HMI30. The route determiner 53 determines, for example, a route from aposition of the own vehicle M identified by the GNSS receiver 51 (or anyinput position) to a destination input by the occupant using thenavigation HMI 52 (hereinafter referred to as a route on a map) withreference to the first map information 54. The first map information 54is, for example, information in which a road shape is expressed by linksindicating roads and nodes connected by the links. The first mapinformation 54 may include curvatures of roads and point of interest(POI) information. The route on the map is output to the MPU 60. Thenavigation device 50 may perform route guidance using the navigation HMI52 based on the route on the map. The navigation device 50 may beimplemented by, for example, a function of a terminal device such as asmartphone or a tablet terminal possessed by the occupant. Thenavigation device 50 may transmit a present position and a destinationto a navigation server via the communication device 20 to acquire thesame route as the route on the map from the navigation server.

The MPU 60 retains, for example, second map information 62 in a storagedevice such as an HDD or a flash memory in addition to a recommendedlane determiner 61. The recommended lane determiner 61 divides a routeon a map provided from the navigation device 50 into a plurality ofblocks (for example, divides the route in a vehicle movement directionfor each 100 [m]) and determines a recommended lane for each block withreference to the second map information 62. The recommended lanedeterminer 61 determines in which lane the vehicle travels from theleft. When there is a branching location in the route on the map, therecommended lane determiner 61 determines a recommended lane so that theown vehicle M can travel in a reasonable route to move to a branchingdestination.

The second map information 62 is map information that has higheraccuracy than the first map information 54. The second map information62 includes, for example, information regarding the middles of lanes orinformation regarding boundaries of lanes. The second map information 62may include road information, traffic regulation information, addressinformation (address and postal number), facility information, andtelephone number information. The second map information 62 may beupdated frequently by causing the communication device 20 to communicatewith another device.

The driving operator 80 includes, for example, an accelerator pedal, abrake pedal, a shift lever, a steering wheel, a heteromorphic steeringwheel, a joystick, and other operators. A sensor that detects anoperation amount or presence or absence of an operation is mounted onthe driving operator 80. The detection result is output to the automateddriving control device 100 or some or all of the travel driving poweroutput device 200, the brake device 210, and the steering device 220.

The automated driving control device 100 includes, for example, a firstcontroller 120 and a second controller 160. Each of the first controller120 and the second controller 160 is implemented, for example, bycausing a hardware processor such as a central processing unit (CPU) toexecute a program (software). Some or all of the constituent elementsmay be implemented by hardware (a circuit unit including circuitry) suchas a large scale integration (LSI), an application specific integratedcircuit (ASIC), a field-programmable gate array (FPGA), or a graphicsprocessing unit (GPU) or may be implemented by software and hardware incooperation. The program may be stored in advance in a storage device (astorage device including a non-transitory storage medium) such as an HDDor a flash memory of the automated driving control device 100 or may bestored in a storage medium such as a DVD or a CD-ROM which can bedetachably mounted, and a storage medium (a storage device including anon-transitory storage medium) may be mounted on a drive device to beinstalled in an HDD or a flash memory of the automated driving controldevice 100. A combination of the object recognition device 16 and theautomated driving control device 100 is an example of a “mobile objectcontrol device.” A combination of the action plan generator 140 and thesecond controller 160 is an example of a “driving controller.”

FIG. 2 is a diagram illustrating a functional configuration of the firstcontroller 120 and the second controller 160. The first controller 120includes, for example, a recognizer 130 and an action plan generator140. The first controller 120 implements, for example, a function byartificial intelligence (AI) and a function by a model given in advanceconcurrently. For example, a function of “recognizing an intersection”is realized by performing recognition of an intersection by deeplearning or the like and recognition based on a condition given inadvance (a signal, a road sign, or the like which can be subjected topattern matching) concurrently, scoring both the recognitions, andperforming evaluation comprehensively. Thus, reliability of theautomated driving is guaranteed.

The recognizer 130 recognizes a position, a speed, an acceleration, andthe like of an object which is around the own vehicle M based oninformation input from the camera 10, the radar device 12, and the LIDAR14 via the object recognition device 16. For example, the position ofthe object is recognized as a position on the absolute coordinates inwhich a representative point (a center of gravity, a center of a drivingshaft, or the like) of the own vehicle M is the origin and is used forcontrol. The position of the object may be represented as arepresentative point such as a center of gravity, a corner, or the likeof the object or may be represented as expressed regions. A “state” ofan object may include both an acceleration and a jerk of the object oran “action state” (for example, whether a vehicle is changing a lane oris attempting to change the lane).

The recognizer 130 recognizes, for example, a lane in which the ownvehicle M is traveling (a traveling lane). For example, the recognizer130 recognizes the traveling lane by comparing patterns of road marklines (for example, arrangement of continuous lines and broken lines)obtained from the second map information 62 with patterns of road marklines around the own vehicle M recognized from images captured by thecamera 10. The recognizer 130 may recognize an own lane by recognizingrunway boundaries (road boundaries) including road mark lines orshoulders, curbstones, median strips, and guardrails without beinglimited to road mark lines. In this recognition, the position of the ownvehicle M acquired from the navigation device 50 or a process result byINS may be added. The recognizer 130 recognizes temporary stop lines,obstacles, red signals, toll gates, signs, signboards, and other roadevents.

The recognizer 130 recognizes a position or posture of the own vehicle Mwith respect to a traveling lane when the recognizer 130 recognizes thetraveling lane. For example, the recognizer 130 may recognize adeviation from the middle of a lane of the standard point of the ownvehicle M and an angle formed with a line extending along the middle ofa lane in the traveling direction of the own vehicle M as a relativeposition and posture of the own vehicle M with respect to the travelinglane. Instead of this, the recognizer 130 may recognize a position orthe like of the standard point of the own vehicle M with respect to anyside end portion (a road mark line or a road boundary) of the travelinglane as the relative position of the own vehicle M to the travelinglane.

In the embodiment, the recognizer 130 particularly includes a firstdeterminer 130A, a second determiner 130B, a merging position candidatesetter 130C, a third determiner 130D, a merging position selector 130E,and a brake position estimator 130F. The functional details will bedescribed below.

The action plan generator 140 generates a future target trajectory alongwhich the own vehicle M travels automatedly (without depending on amanipulation by a driver) so that the own vehicle M travels in arecommended lane determined by the recommended lane determiner 61 inprinciple and deals with a surrounding situation of the own vehicle M.The target trajectory includes, for example, a position element. Forexample, the target trajectory is expressed by arranging points(trajectory points) in order at which the own vehicle M will arrive. Thetrajectory points are locations at which the own vehicle M will arrivefor each predetermined traveling distance (for example, about several[m]) at a distance along a road. Apart from this, a target speed and atarget acceleration for each a predetermined sampling time (for example,about every fractions of a second) are generated as part of the targettrajectory. The trajectory points may be positions at which the ownvehicle M will arrive at the sampling time for each predeterminedsampling time. In this case, information regarding the target speed orthe target acceleration is expressed at intervals of the trajectorypoints.

The action plan generator 140 may set an automated driving event when atarget trajectory is generated. As automated driving events, there are aconstant speed traveling event, a low speed following traveling event, alane changing event, a branching event, a merging event, a takeoverevent, and the like. The action plan generator 140 generates a targettrajectory in accordance with a started event.

The second controller 160 controls the travel driving power outputdevice 200, the brake device 210, and the steering device 220 such thatthe own vehicle M passes along the target trajectory generated by theaction plan generator 140 at a scheduled time.

Referring back to FIG. 2, the second controller 160 includes, forexample, an acquirer 162, a speed controller 164, and a steeringcontroller 166. The acquirer 162 acquires information regarding thetarget trajectory (trajectory points) generated by the action plangenerator 140 and stores the information in a memory (not illustrated).The speed controller 164 controls the travel driving power output device200 or the brake device 210 based on speed elements subsidiary to thetarget trajectory stored in the memory. The steering controller 166controls the steering device 220 in accordance with a curved state ofthe target trajectory stored in the memory. Processes of the speedcontroller 164 and the steering controller 166 are implemented realized,for example, by combining feed-forward control and feedback control. Forexample, the steering controller 166 performs the feed-forward controlin accordance with a curvature of a road in front of the own vehicle Mand the feedback control based on deviation from the target trajectoryin combination.

The travel driving power output device 200 outputs travel driving power(toque) for allowing a vehicle to travel to a driving wheel. The traveldriving power output device 200 includes, for example, a combination ofan internal combustion engine, an electric motor, and a transmission anda power electronic controller (ECU) controlling them. The power ECUcontrols the foregoing configuration in accordance with informationinput from the second controller 160 or information input from thedriving operator 80.

The brake device 210 includes, for example, a brake caliper, a cylinderthat transmits a hydraulic pressure to the brake caliper, an electronicmotor that generates a hydraulic pressure to the cylinder, and a brakeECU. The brake ECU controls the electric motor in accordance withinformation input from the second controller 160 or information inputfrom the driving operator 80 such that a brake torque in accordance witha brake manipulation is output to each wheel. The brake device 210 mayinclude a mechanism that transmits a hydraulic pressure generated inresponse to a manipulation of the brake pedal included in the drivingoperator 80 to the cylinder via a master cylinder as a backup. The brakedevice 210 is not limited to the above-described configuration and maybe an electronic control type hydraulic brake device that controls anactuator in accordance with information input from the second controller160 such that a hydraulic pressure of the master cylinder is transmittedto the cylinder.

The steering device 220 includes, for example, a steering ECU and anelectric motor. The electric motor works a force to, for example, a rackand pinion mechanism to change a direction of a steering wheel. Thesteering ECU drives the electric motor to change the direction of thesteering wheel in accordance with information input from the secondcontroller 160 or information input from the driving operator 80.

Operation

Next, a process of the mobile object control device according to anembodiment will be described with reference to FIGS. 3 to 8. FIG. 3 is adiagram illustrating an example of a scenario in which a process of themobile object control device according to the embodiment is performed.In FIG. 3, between merging lanes ML including two lanes L1 and L2, theown vehicle M is traveling in the merging lane L2 closer to a mergedlane L3, and another vehicle M1 is traveling in the merging lane L1farther from the merged lane L3. Further, other vehicles M2 and M3 aretraveling in the merged lane L3. In order for the own vehicle M to enterthe merged lane L3, the mobile object control device determines amerging position on the merged lane L3. On the other hand, since theother vehicle M1 attempts to enter the merged lane L3, it is necessaryfor the mobile object control device to determine a merging position onthe merged lane L3 in consideration of entrance of the other vehicle M1to the merged lane L3. The present invention is devised to determine amerging position in such a situation and utilize automated driving ordriving support.

When an image of an outside space of the own vehicle M captured by thecamera 10 is acquired from the image acquirer 16A, the first determiner130A determines whether the own vehicle M is in a merging lane L2(hereinafter a merging lane closer to the merged lane L3 is simplyreferred to as the “merging lane L2”) closer to the merged lane L3between the two merging lanes ML based on the image. Specifically, forexample, when the second map information 62 indicates the merging laneL2 or the image of the outside space of the own vehicle M indicates themerging lane L2 or indicates a dashed-line shape specific to a junctionroad with two lanes, the first determiner 130A determines that the ownvehicle M is in the merging lane L2. In the case of FIG. 3, the firstdeterminer 130A determines that the own vehicle M is in the merging laneL2.

When the first determiner 130A determines that the own vehicle M is inthe merging lane L2, the second determiner 130B determines whetheranother vehicle is in the merging lane L1 (hereinafter a merging lanefarther from the merged lane L3 is simply referred to as the “merginglane L1”) farther from the merged lane L3 of the merging lane ML infront of the own vehicle M. Specifically, for example, with the camera10, the second determiner 130B determines whether another vehicle is inthe merging lane L1 in front of the own vehicle M. Here, “in front ofthe own vehicle M” means that, for example, the front end of the othervehicle is ahead of the front end of the own vehicle M in a travelingdirection of the own vehicle M. In the case of FIG. 3, since the frontend of the other vehicle M1 is ahead of the front end of the own vehicleM and the other vehicle M1 is in the merging lane L1, the seconddeterminer 130B determines that the other vehicle is in the merging laneL1 in front of the own vehicle M. Instead of this, “in front of the ownvehicle M” may mean that the center of gravity of the other vehicle isahead of the center of gravity of the own vehicle M or may mean that thefront end of the other vehicle is ahead of the rear end of the ownvehicle.

The merging position candidate setter 130C sets one or more mergingposition candidates CP at which merging of the own vehicle M to themerged lane L3 is completed and which are set as relative positionsbetween vehicles in the merged lane L3. Specifically, for example, themerging position candidate setter 130C identifies a plurality of othervehicles in the merged lane L3 shown in an image captured by the camera10 and determines whether the own vehicle M can enter the merged lane L3on the premise that restrictions (an upper limit and a lower limit) of aspeed, an acceleration, and a yaw rate are satisfied, based on relativedistances and relative speeds of the plurality of other vehicles to theown vehicle M. When it is determined that the entrance is possible,merging position candidates CP are extracted as relative positionsbetween the other vehicles located in front or to the rear of spaces inwhich the entrance is possible. In the case of FIG. 3, the mergingposition candidate setter 130C sets a position CP1 between the othervehicles M2 and M3 and a position CP2 to the rear of the other vehicleM3 as the merging position candidates CP.

The second determiner 130B can utilize the merging position candidatesCP set by the merging position candidate setter 130C in order todetermine whether other vehicles are in front of the own vehicle M. Forexample, in the case of FIG. 3, the second determiner 130B sets aperpendicular in the traveling direction of the own vehicle M drawn fromthe merging position candidate CP1 located in front with respect to thetraveling direction of the own vehicle M as a virtual line VL on anassumed plane virtually seen from the above and compares a firstdistance D1 between the own vehicle M and the virtual line VL with asecond distance D2 between the other vehicle M1 and the virtual line VL.When the second distance D2 is shorter than the first distance D1, itcan be determined that the other vehicle M1 is in front of the ownvehicle M.

The third determiner 130D estimates a traveling trajectory of the othervehicle and determines whether the other vehicle is able to merge to themerging position candidate CP1 located in front, based on the estimatedtraveling trajectory. Specifically, for example, the third determiner130D estimates a speed vector or an acceleration vector of the othervehicle using the camera 10, the radar device 12, or the LIDAR 14 andgenerates a trajectory of the other vehicle with a straight line or acurved line based on the measurement information. In the case of FIG. 3,the third determiner 130D estimates a traveling trajectory PT of theother vehicle M1 merging to the merging position candidate CP1, andtherefore determines that the other vehicle M1 can merge to the mergingposition candidate CP1.

The merging position selector 130E selects a merging position at whichthe merging of the own vehicle M to the merged lane L3 is completed fromone or more merging position candidates CP set by the merging positioncandidate setter 130C. At this time, when the second determiner 130Bdetermines that the other vehicle is in the merging lane L1 in front ofthe own vehicle M, the merging position selector 130E selects a mergingposition from the merging position candidates CP excluding the mergingposition candidate CP1 located in front with respect to the travelingdirection of the own vehicle M among the one or more merging positioncandidates CP. In the case of FIG. 3, since the other vehicle M1 istraveling on the front left side of the own vehicle M, the mergingposition selector 130E selects a merging position from the mergingposition candidates CP excluding the merging position candidate CP1.That is, the merging position selector 130E selects the merging positioncandidate CP2 as the merging position.

On the other hand, even if the second determiner 130B determines thatthe other vehicle is in the merging lane L1 in front of the own vehicleM, the other vehicle does not reach the merging position candidate CP1when the traveling trajectory to the merging position candidate CP1located in front is not ended. In this case, when the merging positionselector 130E selects the merging position candidate CP2 as the mergingposition, the other vehicle cannot change the lane to the merged laneL3.

Accordingly, when the third determiner 130D determines that the othervehicle cannot merge to the merging position candidate CP1 located infront, the merging position selector 130E selects a merging positionfrom the merging position candidate CP excluding the merging positioncandidate CP1 located in front and the merging position candidate CP2located in a second place in the traveling direction of the own vehicleM among the one or more merging position candidates CP. FIG. 4 is adiagram illustrating an example of a scenario in which the mergingposition selector 130E selects a merging position when the thirddeterminer 130D determines that the other vehicle cannot merge to themerging position candidate CP1 located in front. In FIG. 4, the thirddeterminer 130D determines that the traveling trajectory is not ended tothe merging position candidate CP1 from the other vehicle M1. Therefore,the merging position selector 130E selects a merging position candidateCP3 as the merging position from the merging position candidates CPexcluding the merging position candidate CP1 located in front and themerging position candidate CP2 located in the second place in thetraveling direction of the own vehicle M among the merging positioncandidates CP. Thus, both the own vehicle M and the other vehicle M1 canperform lane change to the merged lane L3.

Even if the merging position selector 130E selects a merging positionfrom the merging position candidates CP excluding the merging positioncandidate CP1 located in front, another vehicle is subsequentlydecelerated, and the own vehicle M is located in front of the othervehicle, the merging position selector 130E keeps this selection. FIG. 5is a diagram illustrating an example of a scenario in which the ownvehicle M is located in front of the other vehicle as a result ofdeceleration of the other vehicle after the merging position selector130E selects a merging position. In FIG. 5, the merging positionselector 130E selects the merging position candidate CP2 as a mergingposition. Subsequently, as a deceleration result of the other vehicleM1, the own vehicle M is located in front of the other vehicle M1. Inthis case, the merging position selector 130E keeps a selection resultof the merging position candidate CP2 as the merging position. Thus, itis possible to prevent hunting of an operation of selecting the mergingposition and it is possible to stabilize a behavior of the own vehicleM.

Next, an exemplary flow of the mobile object control device according tothe embodiment will be described with reference to FIG. 6. FIG. 6 is aflowchart illustrating an exemplary flow of a process of the mobileobject control device according to the embodiment. The mobile objectcontrol device performs the process of the flowchart at a predeterminedcontrol cycle (for example, 10 milliseconds).

First, the mobile object control device causes the image acquirer 16A toacquire an image obtained by imaging an outside space of the own vehicleM using the camera 10 (step S100). Subsequently, based on the imageacquired from the image acquirer 16A, the mobile object control devicecauses the first determiner 130A to determine whether the own vehicle Mis in the merging lane L2 closer to the merged lane L3 between the twomerging lanes ML (step S101). When it is determined that the own vehicleM is not in the merging lane L2, the mobile object control devicereturns the process to step S100.

Conversely, when the own vehicle M is in the merging lane L2, the mobileobject control device causes the merging position candidate setter 130Cto set one or more merging position candidates CP at which merging ofthe own vehicle M to the merged lane L3 is completed (step S102).Subsequently, the mobile object control device causes the seconddeterminer 130B to determine whether another vehicle is in the merginglane L1 farther from the merged lane L3 between the merging lanes ML infront of the own vehicle M (step S103). When it is determined thatanother vehicle is not in the merging lane L1 in front of the ownvehicle M, the mobile object control device causes the merging positionselector 130E to select the front merging position candidate CP1 as themerging position among one or more merging position candidates CP (stepS104).

Conversely, when it is determined that another vehicle is in the merginglane L1 in front of the own vehicle, the mobile object control devicecauses the third determiner 130D to estimate a traveling trajectory ofthe other vehicle and determines whether the other vehicle is able tomerge to the merging position candidate CP1 located in front, based onthe estimated traveling trajectory (step S105). When it is determinedthat the other vehicle is able to merge to the merging positioncandidate CP1, the mobile object control device causes the mergingposition selector 130E to select a merging position from the mergingposition candidates excluding the front merging position candidate CP1among the one or more merging position candidates CP (step S106).

Conversely, when it is determined that the other vehicle is not able tomerge to the merging position candidate CP1, the mobile object controldevice causes the merging position selector 130E to select a mergingposition candidate as the merging position from the merging positioncandidates CP excluding the merging position candidate CP1 located infront and the merging position candidate CP2 located in the second placein the traveling direction of the own vehicle M among the one or moremerging position candidates CP (step S107). Subsequently, the mobileobject control device causes the action plan generator 140 to generate atarget trajectory of the own vehicle M for merging to the selectedmerging position. Then, the process of the flowchart ends.

In the foregoing flowchart, the case in which the number of othervehicles in front of the own vehicle M is one has been described.However, the application of the present invention is not limited to sucha situation. For example, when the number of other vehicles in front ofthe own vehicle M is plural, the merging position selector 130E mayselect a merging position in accordance with the number of othervehicles. Specifically, for example, in step S105, when a plurality ofother vehicles are able to merge to the merging position candidate CP1,the merging position selector 130E may select a merging position formmerging position candidates excluding the front merging positioncandidate CP1 to the same number of merging position candidates CP amongthe merging position candidates CP.

MODIFIED EXAMPLE

In the foregoing embodiment, the example in which the mobile objectcontrol device according to the present invention is applied toautomated driving has been described. However, the mobile object controldevice according to the present invention is not limited to theconfiguration and can also be applied to manual driving. In this case,instead of the driving controller, the mobile object control deviceaccording to the embodiment may further include a driving instructorthat generate a target trajectory based on a selected merging positionand gives at least one of a steering instruction and anacceleration/deceleration instruction so that an occupant of the ownvehicle M performs driving along the generated target trajectory. Thedriving instructor can be implemented as, for example, a part of thefunction of the navigation devices 50.

When the mobile object control device according to the present inventionis applied to manual driving, the mobile object control device mayfurther include a brake time estimator that estimates a time until anoccupant of the own vehicle M manipulates the brake device 210, that is,a time to brake (TTD). In this case, when a time estimated by the braketime estimator is less than a threshold, the merging position selector130E may determine that an occupant of the own vehicle M cannot affordto manipulate the brake device 210 and may select a merging positionfrom all the merging position candidates CP without excluding themerging position candidate CP1 located in front with respect to thetraveling direction of the own vehicle M. Thus, it is possible to selecta merging position flexibly in accordance with a situation of theoccupant of the own vehicle M.

According to the above-described present invention, the mobile objectcontrol device determines whether another vehicle traveling in front ofthe own vehicle in a merging lane farther from a merged lane when thenumber of merging lanes in which the own vehicle M travels is two. Inaccordance with a determination result, a merging position is selected.Thus, it is possible to appropriately indicate a merging position whenthe number of merging lanes is two.

The above-described embodiments can be expressed as follows.

A mobile object control device including:

a storage device storing a program; and

a hardware processor,

wherein the hardware processor executes the program stored in thestorage device to:

acquire an image obtained by imaging an outside space of a mobileobject;

determine whether the mobile object is in a merging lane closer to amerged lane between two merging lanes, based on the image;

determine whether another mobile object is in a merging lane fartherfrom the merged lane between the merging lanes in front of the mobileobject when it is determined that the mobile object is in the closermerging lane;

set one or more merging position candidates at which merging of themobile object to the merged lane is completed and which are positionsbetween mobile objects in the merged lane;

select a merging position at which the merging of the mobile object tothe merged lane is completed from the one or more merging positioncandidates; and

select the merging position from the merging position candidatesexcluding a merging position candidate located in front with respect toa traveling direction of the mobile object among the one or more mergingposition candidates when the hardware processor determines that thereare other mobile objects.

The embodiments for carrying out the present invention have beendescribed above, but the present invention is not limited to theembodiments. Various modifications and substitutions can be made withinthe scope of the present invention without departing from the gist ofthe present invention.

What is claimed is:
 1. A mobile object control device comprising: astorage device storing a program; and a hardware processor, wherein thehardware processor executes the program stored in the storage device to:acquire an image obtained by imaging an outside space of a mobileobject; determine whether the mobile object is in a merging lane closerto a merged lane between two merging lanes, based on the image;determine whether another mobile object is in a merging lane fartherfrom the merged lane between the merging lanes in front of the mobileobject when it is determined that the mobile object is in the closermerging lane; set one or more merging position candidates at whichmerging of the mobile object to the merged lane is completed and whichare positions between mobile objects in the merged lane; and select amerging position at which the merging of the mobile object to the mergedlane is completed from the one or more merging position candidates;wherein the hardware processor selects the merging position from themerging position candidates excluding a merging position candidatelocated in front with respect to a traveling direction of the mobileobject among the one or more merging position candidates when it isdetermined that there are other mobile objects.
 2. The mobile objectcontrol device according to claim 1, wherein the hardware processorsets, as a virtual line, a perpendicular drawn from the merging positioncandidate located in front with respect to the traveling direction ofthe mobile object on an assumed plane virtually seen from the above,compares a first distance between the mobile object and the virtual linewith a second distance between the other mobile object and the virtualline, and determines that the other mobile object is in front of themobile object when the second distance is shorter than the firstdistance.
 3. The mobile object control device according to claim 1,wherein the hardware processor estimates a traveling trajectory of theother mobile object and determines whether the other mobile object isable to merge to the merging position candidate located in front basedon the traveling trajectory, and wherein, when the hardware processordetermines that the other mobile object is not able to merge to themerging position candidate located in front, the hardware processorselects the merging position from the merging position candidatesexcluding a merging position candidate located in front and a mergingposition candidate located in a second place in the traveling directionof the mobile object among the one or more merging position candidates.4. The mobile object control device according to claim 1, wherein thehardware processor estimates a time until an occupant of the mobileobject manipulates a brake device of the mobile object, and wherein,when the estimated time is less than a threshold, the hardware processorselects the merging position from the one or more merging positioncandidates without excluding the merging position candidate located infront with respect to the traveling direction of the mobile object. 5.The mobile object control device according to claim 1, wherein thehardware processor keeps selecting the merging position even when theother mobile object is decelerated after the selection of the mergingposition from the merging position candidates excluding the mergingposition candidate located in front.
 6. The mobile object control deviceaccording to claim 1, wherein the hardware processor generates a targettrajectory of the mobile object merging to the selected merging positionand controls steering and acceleration or deceleration of the mobileobject without depending on a manipulation of a driver of the mobileobject such that the mobile object travels along the generated targettrajectory.
 7. A mobile object control method for causing a computermounted in a vehicle to: acquire an image obtained by imaging an outsidespace of a mobile object; determine whether the mobile object is in amerging lane closer to a merged lane between two merging lanes, based onthe image; determine whether another mobile object is in a merging lanefarther from the merged lane between the merging lanes in front of themobile object when it is determined that the mobile object is in thecloser merging lane; set one or more merging position candidates atwhich merging of the mobile object to the merged lane is completed andwhich are positions between mobile objects in the merged lane; select amerging position at which the merging of the mobile object to the mergedlane is completed from the one or more merging position candidates; andselect the merging position from the merging position candidatesexcluding a merging position candidate located in front with respect toa traveling direction of the mobile object among the one or more mergingposition candidates when the hardware processor determines that thereare other mobile objects.
 8. A computer-readable non-transitory storagemedium that stores a program for causing a computer mounted in a mobileobject to: acquire an image obtained by imaging an outside space of amobile object; determine whether the mobile object is in a merging lanecloser to a merged lane between two merging lanes, based on the image;determine whether another mobile object is in a merging lane fartherfrom the merged lane between the merging lanes in front of the mobileobject when it is determined that the mobile object is in the closermerging lane; set one or more merging position candidates at whichmerging of the mobile object to the merged lane is completed and whichare positions between mobile objects in the merged lane; select amerging position at which the merging of the mobile object to the mergedlane is completed from the one or more merging position candidates; andselect the merging position from the merging position candidatesexcluding a merging position candidate located in front with respect toa traveling direction of the mobile object among the one or more mergingposition candidates when the hardware processor determines that thereare other mobile objects.